Although in general terms the present veterinary method may be applied to all animals suffering from mastitis conditions, it will be largely illustrated with particular reference to dairy cattle. In short, mastitis is a condition caused by bacterial invasion of the milking organs resulting inter alia in painful inflammation and unwanted secretion. Numerous microorganisms are thought to contribute to the problem, but a handful of causative organisms are most common and hence serious, e.g. Staph. coagulase positive, Str. dysgalactiae, uberis and agalactiae and E. coli. "Summer mastitis" is commonly vectored by flies in non-lactating animals. In "sub-clinical" cases, animals suffer from the condition and may act as a source of infection, but do not manifest the full symptoms.
For many years, mastitis in dairy cattle has been treated by infusing comparatively small quantities of antibiotic suspensions into the udder after voiding as far as possible Numerous such materials have been used and all involve several problems for the farmer/producer and the user/consumer.
As current antibiotics are long-acting after a course of treatment, the milking udder continues to excrete antibiotic-containing milk The levels diminish with time, but remain problematic generally for between 6 and 10 milkings. During this period, the milk contains sufficient antibiotic active to inhibit significantly the growth of organisms in the milk, in particular those required for processing the milk into yoghurt or cheese, and also to have marked effects on the intestinal flora of consumers, particularly young children with high milk intake and low body weight. Also, it is generally recognized that a proportion of the population have allergic reactions to some antibiotics, particularly penicillins. For such reasons, in countries with legislation effectively controlling the sales of antibiotics, there are prescribed acceptable levels of antibiotic residues. Generally, the movement of such maxima is downwards and hence the period for which an animal's milk must be withheld from supply (i.e. discarded) is increasing. The use of prophylactic chlorine teat dips is also known.
It has now been found that (mon)oxychlorosene or sodium oxychlorosene in an aqueous medium is an effective treatment for mastitis in a lactating or non-lactating dairy animal. Such does not preclude other treatments and may indeed cooperate therewith. The active ingredient is known for use in human medicine as a disinfectant, but has never been suggested for veterinary use, specifically for the treatment of mastitis by infusion.
In general terms, the present invention relates to a method for treating mastitis which comprises the use of an infusion of an effective amount of (mon)oxychlorosene or sodium oxychlorosene in an aqueous carrier. Inter alia, the present invention provides the use of (mon)oxychlorosene or sodium oxychlorosene for the manufacture of a veterinary infusion medicament for treatment of mastitis. According to the present invention, the compositions used comprise the above active ingredient in an aqueous medium, which may be water or, preferably, saline solution. It is important that the infusion be prepared at the time of use.
According to Martindale, The Extra Pharmacopoeia, (mon)oxychlorosene is the hypochlorous acid complex of a mixture of the phenyl sulphonate derivatives of aliphatic hydrocarbons. It is a fine white powder, which dissolves slowly in water and then hydrolyses rapidly. It is currently commercially available under the trade name "Clorpactin".
Aqueous solutions of sodium (mon)oxychlorosene, in particular in physiological saline, prepared at the point of use, and infused into an infected cow's quarter udder have now been shown to be efficacious in treating mastitis. Generally, a course of 3 or 4 infusions is sufficient to alleviate the clinical symptoms of the condition. This is comparable with conventional antibiotic treatment.
The present active ingredient is thought to react in the infused quarter by releasing hypochlorous acid gas into the udder cavity and hence killing invading organisms. It is relatively short, but very strong acting. The active ingredient hence degrades during the reaction leaving a small amount of residue in the milk and subsequently extracted from the treated quarter(s), but such residue is non-inhibitory to all currently-recognized tests for inhibitory substances In particular, it will not affect cheese and yoghurt starter cultures and is of proven low toxicity. For such reasons, it is possible to use the milk with only one milking needing to be discarded after a course of treatment.
Unlike treatment with antibiotics which may be systematically absorbed, the present method allows non-affected quarters to be milked normally during a course of treatment. Also, while some bacteria may prove antibiotic resistant, the same cannot be said in relation to the present active ingredient.
The present treatment utilizes dilute aqueous solutions of the active ingredient, for example up to 2.5% w/v. Commonly, a course of treatment would involve the use of, say, from 4 to 6 infusions of 40 ml aliquots of 1.25% w/v solutions. Normally, a course of treatment would coincide with the milking schedule over several days, but if desired the voiding/infusing might be repeated, say, hourly, so that an animal could be back "on-line" the next day, for example. Moreover, bearing in mind the problem of sub-clinical mastitis, periodic preventative treatments might be considered as minimal disruption would be involved.
Conventionally, an infusion of freshly-prepared material would be given using a syringe. However, the present invention also relates to a mastitis treatment infusion applicator which may advantageously be used for this purpose. For the present use, such an applicator is provided charged in separate compartments with the active ingredient and the vehicle, mixing being accomplished when required.